1. Field of the invention
The present invention relates to a seat for heavy equipment having a buffer means in forward and backward directions, which can attenuate impact and vibration generated in a cab in forward and backward directions of the heavy equipment (i.e., an X-axis direction in which the heavy equipment travels) during working or traveling of the heavy equipment.
More particularly, the present invention relates to a seat for heavy equipment having a buffer means in forward and backward directions, which can protect an operator by attenuating impact and vibration generated in a cab in forward and backward directions of the heavy equipment in accordance with the driving of the buffer means selected by the operator in a main working mode of the heavy equipment such as excavating, loading rocks and dumping, traveling, or the like.
2. Description of the Prior Art
Generally, main working modes of an excavator include excavating, traveling, loading rocks and dumping, braking, and the like. Since the excavator works in very inferior environments and handles heavy loads, working devices such as a boom and so on are made of hard and rigid materials.
Accordingly, strong impact and vibration generated during the working of the equipment are directly transferred to the equipment through an upper swing structure. Since an operator, who repeats the same work in a specified operating posture, is exposed to such impact and vibration for many hours, the operator fatigue is increased and the working efficiency is lowered.
When the excavator is in the main working mode, impacts are generated in forward and backward directions (i.e., X-axis direction in which the equipment travels), in left and right directions (i.e., Y-axis direction), and in upward and downward directions (i.e., vertical direction or Z-axis direction).
It can be confirmed by experiments that impacts due to vibration generated in forward and backward directions are relatively larger than those due to vibration generated in left and right directions or in upward and downward directions.
As illustrated in FIG. 1, a conventional seat for heavy equipment having buffer means includes a seat 3 composed of a seat part 1 and a seat back part 2; and a suspension 4 (in which buffer means is installed) installed between a cab bottom surface and the seat part 1 to buffer impact and vibration vertically transferred to the seat part 1 through an upper swing structure (not illustrated) during traveling or working of the heavy equipment.
In the drawing, the reference numerals 5 and 6 denote console boxes mounted on left and right sides of the seat part 1 to control working devices, such as a boom, an arm, and the like, in accordance with an output of a manipulation signal corresponding to the amount of manipulation when manipulation levers 7 and 8 are manipulated by an operator.
According to the conventional seat having the buffer means, the impact and vibration, which are generated in upward and downward directions (i.e., Z-axis direction) of the equipment and transferred to the operator through the seat part 1 during the working or traveling of the equipment, can be somewhat attenuated by the buffer function of the suspension 4.
On the other hand, in the main working mode of the excavator, the impact and vibration, which are generated in forward and backward directions (i.e., X-axis direction) of the equipment and transferred to the operator, cannot be attenuated by the buffer function of the suspension 4. Accordingly, the operator is exposed to the impact transferred the suspension 4, and thus easily feels fatigued. Due to this, the reliability and the working efficiency of the expensive equipment may be lowered.